Hioki Hioki FT4310 Manual

HIOKI

FT4310

Instruction Manual

BYPASS DIODE TESTER

99 Washington Street
Melrose, MA 02176

Phone [phone]
Toll Free 1-800-517-8431

Visit us at www.TestEquipmentDepot.com

 
 

EN

Contents

Introduction .........................................................................1

Verifying Package Contents
Safety Information
Operating Precautions

.............................................................. 3

.............................................. 1

....................................................... 8

1

1 Overview 13

1.1 Product Overview .......................................... 13

Names and Functions of Parts ....................14

1.2

2 Preparing for Measurement 21

2.1 Battery Replacement ....................................22

2.2 Using Model L9788-10 Test Lead with

Remote Switch (Red) ....................................24

2.3 How to Use the Carrying Case

(Model C0206) ................................................ 26

3 Measurement 27

3.1 Pre-measurement Inspection ....................... 27

3.2 Auto Power Save (Power-Saving Function) 29

3.3 Auto Backlight-off (Automatic Light-off

Function) ........................................................ 30

3.4 Pass/Fail Judgment (Comparator)

Function ......................................................... 31

Setting the Comparator Function .............................. 32

Canceling the Comparator Function ......................... 32

3.5 Measurement Preparation ............................ 33

3.6 Making Measurements in Voc Mode ............ 34

Comparison Display Function ................................... 35

Auto-hold ..................................................................36

FT4310A961-01

2

3

4

5

6

7

Appx. Index

i

Contents

Negative Voltage Notication Function .....................37

Ground Fault Detection ............................................. 37

3.7 Making Measurements in BPD TEST Mode 38

Lock Function ...........................................................39

Measuring Bypass Diode .......................................... 40

3.8 Bluetooth® Communication Function ..........43

Installing the Smartphone Application Software

GENNECT Cross ...................................................... 44

Pairing the Application Software ...............................45

Making Measurements with the Bluetooth® Function 46

4 Specications 47

4.1 GeneralSpecications .................................47

4.2 Input/Output/MeasurementSpecications . 49

4.3 FunctionSpecications ................................ 54

4.4 InterfaceSpecications ................................ 57

4.5 Factory Settings ............................................ 57

5 Maintenance and Service 59

5.1 Troubleshooting ............................................60

Error Displays and Remedies ................................... 61

Appx. Appx.1

Appx. 1 Measurement Principles ..................Appx.1

Measurement Principles for Bypass Diodes

with an Open Fault .............................................Appx.1

Measurement Principles for Bypass Diodes

with a Short-circuit Fault ....................................Appx.2

ii

Introduction

Introduction

Thank you for purchasing the Hioki FT4310 Bypass Diode Tester. To
obtain maximum performance from the instrument, please read this

Instruction Manual rst, and keep it handy for future reference.

1

Verifying Package Contents

When you receive the instrument, inspect it carefully to ensure
that no damage occurred during shipping. In particular, check the
accessories, panel switches, and connectors. If damage is evident,

or if it fails to operate according to the specications, contact your

authorized Hioki distributor or reseller.

Conrm that these contents are provided.

□ Model FT4310

Bypass Diode Tester

□ Model C0206 Carrying Case □ Model L9788-11

□ Instruction Manual

□ LR6 Alkaline battery × 6

Test Lead Set with Remote Switch

Model L9788-11 is a set of model
L9788-10 Test Lead with Remote Switch
(Red) and EARTH side lead.

2

3

4

5

6

7

Appx. Index

1

Verifying Package Contents

Options

The following options are available for the instrument. Contact your
authorized Hioki distributor or reseller when ordering.

1

2

Product name

Model L9788-92 Breaker Pin CAT III 600 V, 2 A

1

Model L9788-90 Tip Pin CAT III 600 V/CAT II 600 V, 2 A

2

Maximum rated voltage and

maximum rated current

2

Safety Information

Safety Information

This instrument is designed to conform to IEC 61010 Safety
Standards, and has been thoroughly tested for safety prior to
shipment. However, using the instrument in a way not described in
this manual may negate the provided safety features.
Before using the instrument, be certain to carefully read the
following safety notes.

DANGER

Mishandling during use could result in injury or death,
as well as damage to the instrument. Be certain that
you understand the instructions and precautions in
the manual before use.

WARNING

Protective gear
This instrument is measured on a live line. To
prevent an electric shock, use appropriate protective
insulation and adhere to applicable laws and
regulations.

Notation

In this manual, the risk seriousness and the hazard levels are

classied as follows.

DANGER

WARNING

Indicates an imminently hazardous situation that will
result in death or serious injury to the operator.

Indicates a potentially hazardous situation that may result
in death or serious injury to the operator.

1

2

3

4

5

6

7

Appx. Index

3

Safety Information

CAUTION

Indicates a potentially hazardous situation that may result
in minor or moderate injury to the operator or damage to
the instrument or malfunction.

Indicates prohibited actions.

Indicates the action which must be performed.

*

(p. )

[ ]

MEASURE

(Bold)

Additional information is presented below.

Indicates the page of reference information.

Screen displays are enclosed in square brackets.

Indicates the names of keys and other controls on the
instrument.

Symbols on the instrument

Indicates cautions and hazards. When the symbol is
printed on the instrument, refer to a corresponding topic
in the Instruction Manual.

Indicates that dangerous voltage may be present at this
terminal.

Indicates a instrument that has been protected throughout
by double insulation or reinforced insulation.

Indicates a grounding terminal.

Indicates DC (Direct Current).

Indicates AC (Alternating Current).

4

Safety Information

Symbols for various standards

Indicates the Waste Electrical and Electronic Equipment
Directive (WEEE Directive) in EU member states.

Indicates that the product conforms to regulations set out by the
EU Directive.

Indicates that the product incorporates Bluetooth® wireless
technology.

Screen Display

The instrument screen displays the alphanumeric characters as
follows.

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

1 2 3 4 5 6 7 8 9 0

Accuracy

We dene measurement tolerances in terms of rdg. (reading) and

dgt. (digt) values, with the following meanings:

(reading or displayed value)

rdg.

The value currently being measured and indicated on the
measuring instrument.

(resolution)
The smallest displayable unit on a digital measuring instrument,

dgt.

i.e., the input value that causes the digital display to show a “1” as

the least-signicant digit.

1

2

3

4

5

6

7

Appx. Index

5

Safety Information

Trademarks

• Bluetooth® is a registered trademark of Bluetooth SIG, Inc. (USA).
The trademark is used by HIOKI E.E.CORPORATION under
license.

• Android, Google Play are registered trademarks of Google, Inc.

• IOS is a registered trademark of Cisco in the U.S. and other
countries.

• iPhone, iPad, iPad mini, and iPod Touch are trademarks of Apple
Inc.

• The App Store is a service mark of Apple Inc.

6

Safety Information

Measurement Categories

To ensure safe operation of measuring instruments, IEC 61010
establishes safety standards for various electrical environments,
categorized as CAT II to CAT IV, and called measurement
categories.

1

DANGER

• Using a measuring instrument in an environment
designated with a higher-numbered category than
that for which the instrument is rated could result in
a severe accident, and must be carefully avoided.

• Never use a measuring instrument that lacks
category labeling in a CAT II to CAT IV measurement
environment. Doing so could result in a serious
accident.

CAT II: When directly measuring the electrical outlet receptacles of

CAT III: When measuring the primary electrical circuits of heavy equipment

CAT IV: When measuring the circuit from the service drop to the service

the primary electrical circuits in equipment connected to an
AC electrical outlet by a power cord (portable tools, household
appliances, etc.)

(xed installations) connected directly to the distribution panel, and

feeders from the distribution panel to outlets.

entrance, and to the power meter and primary overcurrent
protection device (distribution panel).

Distribution panel

Service entrance

Service drop

CAT IV

Power meter

Internal wiring

CAT III

Fixed installation

CAT II

T

Outlet

2

3

4

5

6

7

Appx. Index

7

Operating Precautions

Operating Precautions

Follow these precautions to ensure safe operation and to obtain the

full benets of the various functions.

DANGER

• For your safe operation, do not connect any test
lead to the primary of the distribution panel.

• Do not short-circuit two wires to be measured by
bringing the test leads into contact with them. Arcs
or such grave accidents are likely to occur.

• To prevent a short-circuit or an electric shock, do
not touch the metal part of the connecting test lead
tip.

• To prevent an electric shock, be careful to avoid
shorting live lines with the test leads tip.

If the test lead or the instrument is damaged, there
is a risk of an electric shock. Perform the following
inspection before using them:

• Before using the instrument, check that the coating
of the test leads are neither ripped nor torn and that
no metal parts are exposed. Using the instrument
under such conditions could result in an electric

shock. Replace the test leads with those specied

by our company.

• Verify that it operates normally to ensure that no
damage occurred during storage or shipping. If you

nd any damage, contact your authorized Hioki

distributor or reseller.

8

Operating Precautions

WARNING

• To prevent an electric shock, a short-circuit and
damage to the instrument, observe the following
precautions: Check the position of the rotary
switch before taking measurements. Disconnect
the test leads from the measurement object before
switching the rotary switch.

• Do not use the instrument with circuits that exceed

its ratings or specications. Doing so may damage

the instrument, resulting in an electric shock.

• Use only the specied test leads. Use of any test

lead not specied by our company does not allow

safe measurements.

• To prevent electrical accidents, remove power from
the circuit before connecting the test leads.

• To prevent an electric shock, do not exceed the
lower of the ratings shown on the instrument and
test leads.

1

2

3

4

5

6

7

Appx. Index

9

Operating Precautions

CAUTION

Observe the following to prevent an electric shock, a
short-circuit, or damage to the instrument.

• Turn off any disconnector devices and separate from
the power conditioner before starting the measurements
for the solar battery panel.

• Solar batteries always generate high voltages especially
in day time. Pay attention to prevent an electric shock
for measurements.

• Do not touch any metal parts such as connection box
and disconnector devices directly with bare hands.
Doing so may cause an electric shock due to the
voltage of the generator.

• Maximum rated voltage to terminal of the instrument is
1000 V DC. Do not use the instrument for equipment
with rated voltage over 1000 V DC. Doing so may cause
an electric shock or damage to the instrument.

• The cable is hardened in freezing temperatures. Do not
bend or pull it to avoid tearing its shield or cutting cable.

• The protection rating for the enclosure of this instrument
(based on EN60529) is IP40*.

* IP40:
This indicates the degree of protection provided by the enclosure of
the instrument for use in hazardous locations, entry of solid foreign
objects, and the ingress of water.

4: Protected against access to hazardous parts with wire measuring 1.0 mm

in diameter.

0: The equipment inside the enclosure is not protected against the harmful

effects of water.

10

Installing the instrument

Installing the instrument in inappropriate locations
may cause a malfunction of instrument or may give
rise to an accident. Avoid the following locations.

• Exposed to direct sunlight or high temperature

• Exposed to corrosive or combustible gases

• Exposed to a strong electromagnetic eld or
electrostatic charge

• Near induction heating systems (such as high-

frequency induction heating systems and IH

cooking equipment)

• Susceptible to vibration

• Exposed to water, oil, chemicals, or solvents

• Exposed to high humidity or condensation

• Exposed to high quantities of dust particles

Operating Precautions

WARNING

1

2

3

4

Precautions when transporting the instrument

During shipment of the instrument, handle it carefully so that it is not
damaged due to a vibration or shock.

11

5

6

7

Appx. Index

Operating Precautions

Handling the Instrument

To avoid damage to the instrument, protect it from physical
shock when transporting and handling it. Be especially
careful to avoid physical shock from due to dropping it.

Test leads

• Removable sleeves are attached to the metal pins
at the end of the test leads. To prevent a short-circuit
accident, be sure to use the test leads with the sleeves
attached when performing measurements in the CAT
III measurement category. Remove the sleeves before
starting CAT II circuit measurements. You can use the
test leads with the sleeve removed for secondary side
of the circuit breakers turned off. (Refer to “Measurement
Categories” (p. 7))

• If the sleeves are inadvertently removed during
measurement, stop the measurement.(p. 26)

CAUTION

CAUTION

12

1

Overview

1.1 Product Overview

This is a measuring instrument to test faults of bypass diodes (BPD)
incorporated in solar power generation systems*.

Can be measured even in day time

• Bypass diode condition can be measured without covering the solar panels.

Easy measurements

• Bypass diode condition can be measured with a connection box.

• Measurement results can be sent to a tablet or other mobile device by

Detecting bypass diode deterioration

• The resistance of the bypass route can be measured and deterioration

*: Strings in parallel conguration or special complex conguration cannot be

measured.

®

Bluetooth

of the bypass diode or increase of connector contact resistance between
modules can be detected.

.

1

2

3

4

5

6

7

Appx. Index

13

Names and Functions of Parts

1.2 Names and Functions of Parts

Front

(p. 19, p. 22, p. 38)

1

Display (p. 17)

Top

32

4

(p. 8)

65 7

MEASURE key (p. 15) Measurement switch

1

N(−) terminal Connect the black test lead.

2

Control terminal

3

P(+) terminal

4

Rotary switch (p. 15)

5

Operation keys (p. 16)

6

Live circuit indicator

7

Connect Model L9788-10 Test Lead with
Remote Switch (Red).

Selects the measurement functions (the
measurement modes) and turns off the
power. (p. 15)

Flashes when voltage remains between
measuring terminals.

14

(p. 8)

MEASURE key

Names and Functions of Parts

MEASURE key

states

Raise the key

Description in

this manual

Changing measurement mode (turning on the power)

Setting the rotary switch in a position other than OFF turns on the power.

Rotary switch

state

Description in

this manual

Voc mode: Measures open-circuit voltages. (p. 34)
BPD TEST mode: Measures bypass diodes and bypass diode resistors.

Turning off the power

Rotary switch

state

Turn on comparison

display or enable

continuous

measurement.

Voc mode BPD TEST mode Self-check mode

Set the rotary

switch in Voc.

(p. 38)

Press the right of

the key

Press the

MEASURE key.

Set the rotary
switch in BPD

TEST.

Retract the key

Release the

MEASURE key.

Set the rotary

switch in SELF

CHECK.

1

2

3

4

5

6

7

Appx. Index

Description in

this manual

Set off the rotary

switch in OFF.

15

Names and Functions of Parts

Operation keys

1

Key name Press

Backlight On/Off Turns off the

LIGHT

1

• In BPD TEST mode:
Switches between
the measurement
screen and the
COUNT mode screen

• When comparator
is set: Decrease of
judgment reference
value (p. 32)

• In Voc or BPD TEST
mode: Moves to
comparator setting
screen.

• When comparator
is set: Increase of
judgment reference
value (p. 32)

• In BPD TEST mode/
self-check mode:
Unlock

In locked state,

RELEASE key

ashes. (p. 39)

2

3

Bluetooth

RELEASE

4

DISPLAY

COMP

(p. 32)

35)

4

51)

®

–

Turn on the instrument

Cancel the auto
power save
function

Turns on the power
in self- check
mode.

Indicates
the number
of capacitor
discharges.

32

Press and hold

(1 second or more)

auto-backlight
function

• When
comparison
display is set:
Reference
value reset
(p.

• COUNT mode
screen: Count
reset (p.

Bluetooth
communication
On/Off (p. 43)

while holding down

–

–

16

Names and Functions of Parts

Display

Open-circuit voltage value (Voc mode, (p. 34)) or bypass route resistance

)

(R

BPR

1

Applied current value

Short-circuit current value
or comparison difference
(p.

35)

Open-circuit voltage value (BPD TEST mode) or reference value (REF,
(p. 35))

Battery indicator (four levels) (p. 28)

Appears when measured voltage is DC.

Flashes when measured voltage is AC.

Flashes when the measured value is less than the minimum
display value.

Flashes when the measured value is greater than the maximum
display value.

Appears when the measured value is retained. (p. 36)

Appears when BPD TEST is PASS (good). (p. 40)
Appears when the judgment is PASS (good) with comparator
function. (p. 31)

Appears when BPD TEST is FAIL (defective). (p. 40)
Appears when the judgment is FAIL (defective) with comparator
function. (p. 31)

Flashes during measurement in BPD TEST mode.

The auto power save function will activate 30 seconds after this

mark starts ashing. (p. 29)

2

3

4

5

6

7

Appx. Index

17

Names and Functions of Parts

Displays Bluetooth® function state. (p. 43)

• On: Bluetooth

• Off: Bluetooth

• Flashes: Bluetooth

®

function On

®

function Off

®

communication active

Appears while in self-check mode.

Appears while in continuous measurement. (p. 15) (p. 35)

Appears when the comparator function is enabled. (p. 31)

Reference value for comparison display measurement in Voc
mode. (p.

35)

Difference between reference value and measured value for
comparison display measurement in Voc mode. (p.

35)

Bypass route resistance

Open-circuit voltage value (p. 34)

Short-circuit current value

Applied current value

Short the test lead when this mark appears during the self-check.

18

Names and Functions of Parts

Model L9788-10 Test Lead with Remote Switch (Red)

CAUTION

The MEASURE key of the instrument is enabled even
when the L9788-10 is connected to the instrument. Note
that the testing voltage is output when the MEASURE
key of the instrument is pressed while the L9788-10 is
connected.

Refer to the L9788-92 Breaker Pin Connection (p. 25)

Sleeve

1 2 3

1

2

3

Enlarged tip view

35

16

1.8

φ

Light

1

MEASURE key

2

Judgment

3

display LED

3.0

φ

Plug

Unit: mm

Lights up interlocked with the backlight of the
instrument.

Measurement switch

• Press: Press the MEASURE key.

• Press and hold: Turns on the comparison display or
enables continuous measurement.

(This operation cannot be performed if the
instrument’s MEASURE key is in the raised position.)

• Lights up in red interlocked with the live wire
warning indicator of the instrument.

Lights up in accordance with the BPD TEST or
comparator judgment result.

• PASS: Green

• FAIL: Red

4

5

6

7

Appx. Index

19

Names and Functions of Parts

20

Preparing for Measurement

2

Insert the batteries. (p. 22)

1

Connect the test leads to the terminals.

2

1

2

N(−) terminal

Connect the black
test lead.

P(+) terminal

Connect the red test
lead.

3

4

5

6

7

Appx. Index

21

Battery Replacement

2.1 Battery Replacement

WARNING

Do not short-circuit, recharge, disassemble or dispose

of in re. Battery may explode if mistreated.

• To prevent an electric shock, release the

MEASURE key, disconnect the test leads from the

measurement object and replace the batteries.

• After replacing the batteries, reattach the cover and
secure the screw before using the instrument.

• To prevent instrument damage or an electric shock,
use only the screw for securing the battery cover
in place that are originally installed. If you have lost

a screw or nd that a screw is damaged, please

contact your authorized Hioki distributor for a
replacement.

CAUTION

Poor performance or damage from battery leakage could
result. Observe the cautions listed below.

• Do not mix new and old batteries, or different types of
batteries.

• Be careful to observe the battery polarity during
installation.

• Do not use batteries after their recommended expiry
date.

• Do not leave depleted batteries inside the instrument.

• Replace batteries only with the specied type.

22

Battery Replacement

• The battery indicator ashes when the remaining battery capacity
is low. In this case, measurement is not possible. Replace the
batteries. (p. 28)

• Handle and dispose of batteries in accordance with local
regulations.

Set the rotary switch in OFF.

1

Disconnect the test leads

OFF

from the instrument.

1

2

Battery (LR6 × 6)
Check the polarity.

+++++

Tabs

Battery cover

+

Screw × 1

Loosen the fastening screw

2

at the rear of the instrument
and remove the battery
cover.

Replace all six batteries.

3

Slide the battery cover back

4

into place and tighten the
screw.

3

4

5

6

7

Appx. Index

23

Using Model L9788-10 Test Lead with Remote Switch (Red)

2.2 Using Model L9788-10 Test Lead with Remote Switch (Red)

Pre-measurement Inspection

Set the rotary

1

switch in OFF.

Fully insert the plug of L9788-10 into

2

terminal P(+) of the instrument.

OK

OFF

Set the rotary switch in SELF CHECK.

3

Press the RELEASE key to cancel the lock function.

4

After [Short the Test Leads] is shown on the display, short

5

the test lead tips with each other.

Press the MEASURE key of the L9788-10.

6

Verify that the display indicates [PASS].

PASS

Lights up in green

7

Press .

Check that the L9788-10 tip
lamp lights up.

24

NO

Using Model L9788-10 Test Lead with Remote Switch (Red)

Replacing the Tip Pin (optional) for Model L9788-10

When the tip pin (L9788-90) of model L9788-10 Test Lead with
Remote Switch (Red) is worn out or broken, it can be replaced. The
tip pin can be purchased via authorized Hioki distributor or reseller.

Set the rotary switch in OFF and

1

OFF

Wrench (size:
7 mm width)

Model L9788-90 Tip Pin

disconnect the L9788-10.

Remove the tip pin by rotating

2

with a wrench.

Attach the new tip pin to the

3

L9788-10 by rotating with a
wrench.

(Tightening torque: 0.3 N·m)

Check the operation.

4

Measure a measurement object of known
values and use after checking that the
resistance is correct.

1

2

3

4

5

Attaching the L9788-92 Breaker Pin

Remove the sleeve of the L9788-10 (p. 26) and attach the breaker
pin.

Fully insert.

Model L9788-92 Breaker Pin

6

7

Appx. Index

25

How to Use the Carrying Case (Model C0206)

Removing and attaching the test lead sleeves

Safely store the removed sleeves so as
not to lose them. (p.

Removing the sleeves Attaching the sleeves

Gently hold the bottom of the
sleeves and pull the sleeves off.

Insert the metal pins of the test leads into

the holes of the sleeves, and rmly push

them all the way in.

12)

2.3 How to Use the Carrying Case (Model C0206)

CAUTION

Attach the strap securely to the four ttings on the carrying

case. If insecurely attached, the instrument may fall and
be damaged when carrying.

Housing

Instruction
manual

*

Belt for the instrument

Secure the strap at 4 positions.

*

26

Model L9788-11 Test Lead Set with
Remote Switch

LR6 Alkaline battery × 6 (Accessory)
Use this space for storing spare batteries
(separately sold) after the accessory
batteries are installed.

Measurement

3

WARNING

Be sure to perform the self-check before using the
instrument. If the instrument is damaged, electric
shock could result.

3.1 Pre-measurement Inspection

Before using the instrument, verify that it operates normally to ensure that no

damage occurred during storage or shipping. If you nd any damage, contact

your authorized Hioki distributor or reseller.

Checking the test lead

Is the white portion
(insulation layer) inside the
cable exposed?

Not Exposed

Checking the instrument

1. Set the rotary switch in
SELF CHECK.

2. Press the RELEASE
key to release the lock
function.

3. Short the test lead tips.

4. Is [PASS] displayed
when the MEASURE key
is pressed?

Displayed
(Go on to the following page)

Exposed

Not
displayed

Do not use any damaged
cables and replace them

with those specied by our

company. This may cause an
electric shock.

The following issues may be
occurring:

• The test lead has not been
inserted all the way.

→ Insert the test lead all the way

in.

• There is a broken connection
in the test lead.

→ Replace them with those

specied by our company.

• Error is displayed.

→ The instrument may have

failed. (p. 61)

1

2

3

4

5

6

7

Appx. Index

27

Pre-measurement Inspection

From the previous page

Checking the remaining battery charge

Is the battery level adequate?

Set the rotary switch in SELF

CHECK and conrm the

battery indicator.

appears

Flashes

Replace the batteries. (p. 22)

Inspection complete

Please read “Operating Precautions” (p. 8) before use.

28

Auto Power Save (Power-Saving Function)

3.2 Auto Power Save (Power-Saving Function)

When the rotary switch is not set in the OFF position, the instrument changes
to the auto power save state 15 minutes after the last operation or live wire
warning indication.
After use, set the rotary switch in OFF. The auto power save feature
consumes a small amount of current.

Disabling the function

1

2

Other than

the OFF
position.

Recovering from auto power save state

Set the rotary switch in OFF and then put it back into place.

Turn on the instrument while

holding down

.

3

4

5

6

7

Appx. Index

29

Auto Backlight-off (Automatic Light-off Function)

3.3 Auto Backlight-off (Automatic Light-off Function)

The backlight of the instrument will automatically turn off after approx. 3
minutes has passed since the last operation.
The automatic light-off function can be canceled when working continuously
in a dark location.

Disabling the function

Backlight: Off

Continuous
short beep

Press for approx. 2 seconds.

Setting the rotary switch in OFF cancels the disabled state.

With the backlight off, press

for approx. 2 seconds

until the instrument beeps
continuously.

30

Pass/Fail Judgment (Comparator) Function

3.4 Pass/Fail Judgment (Comparator) Function

This function compares the measured value with the preset value (= judgment
reference value) and judges whether the result is PASS (good) or FAIL
(defective).
Comparator settings for each mode pass/fail judgment (comparator) will be
saved, even if the rotary switch is set in OFF.

The range that can be set for the reference value is as follows:

DIFF

0 V to ±20 V. The setting allows 1 V increments.

R

BPR

0 Ω to 15 Ω. The setting allows 0.5 Ω increments.

Indication lights up

PASS (good) judgment FAIL (defective) judgment

Indication

1

2

3

4

5

Backlight:

No change

Type of measurements that can be judged

Mode

Voc Reference value or lower

BPD TEST

State of measured value Buzzer Backlight Buzzer

Lower than reference value
and bypass diode is working
correctly

Lights up in

green

PASS judgment FAIL judgment

Backlight:

Lights up in red

Short
beep

Lights up

in red

Lights up in

red

Long
beep

31

6

7

Appx. Index

Pass/Fail Judgment (Comparator) Function

Setting the Comparator Function

Set the rotary switch in the mode for which you wish to set

1

the comparator function.

In BPD TEST mode, press to cancel the lock function. (p. 39)

COMP

1

Flashes

2

3

Press .

2

[COMP] ashes and a value set as

judgment reference value at that
moment is displayed.

Press or to set the

3

reference value.

If you do nothing about 2 seconds
after you set the reference value, the
comparator function will be set, and

[COMP] will appear.

Canceling the Comparator Function

oFF

Press or several times to

select [oFF].

If you do nothing for about 2 seconds after
you select, [COMP] will go out, and the
comparator function will be canceled.

32

Measurement Preparation

3.5 Measurement Preparation

Turn off the main switch of the connection box to be

1

disconnected from the power conditioner.

Turn off all the disconnector devices of the strings.

2

Disconnect lightning arresters from the measuring circuit.

3

Disconnection is not required for the gure (solar generator facility)

shown below because a lightning arrester is not present at the string
side of the disconnector device.

String

2

Off

Disconnector devices

1

Off

Main switch

1

2

3

4

(+)

(-)

P

N

SELF
CHECK

(Example: Solar generator facility)

Lightning

arrester

Connection

box

Power

Conditioner

5

6

7

Appx. Index

33

Making Measurements in Voc Mode

3.6 Making Measurements in Voc Mode

Open-circuit voltage of a string can be measured. Checking the
difference between strings allows determining short-circuit fault.

WARNING

During measurement, do not switch over to other
measurement modes.

Power
Conditioner,
Main switch

(+)

(-)

P

N

4

N(−)

2

3

1

Set the rotary switch in Voc.

1

Connect the black test lead to N(−) of the measurement

2

object.

Connect the red test lead to P(+) of the measurement

3

object.

Check the displayed value.

4

[Voc] shows the measured value (open-circuit voltage value).

34

P(+)

String

Making Measurements in Voc Mode

Comparison Display Function

You can check the difference between the reference value and the
measured value while measuring the open-circuit voltage of solar
battery string.

Raise the MEASURE key of the

HOLD

1

ashes

1

instrument or press and hold the

MEASURE key of the L9788-10.

[HOLD] ashes and [CONT] appears.

1

2

CONT

Connect the test lead to the

appears

HOLD

Example measurement results display

Example measurement results display

Voc=338 V, REF=348 V,
DIFF= −10 V

To reset the reference value, press and hold the DISPLAY key.

2

measurement object.

[HOLD] appears and [Voc] and [REF]

show their measured values.

Connect the test lead to the next

3

measurement object.

[Voc] shows the measured value and
[DIFF] shows the difference with the
[REF] (the reference value).

When the comparator function is
enabled, [PASS] or [FAIL] is displayed.

3

4

5

6

7

Appx. Index

35

Making Measurements in Voc Mode

Auto-hold

With the comparison display function, when the measured value
stabilizes, a short beep is emitted and the measured value is
automatically retained.

When the measured value is 20 V or higher and stabilizes for

approx. 1 second (uctuation range is within 20 V), the measured

value is automatically retained.

When the test leads are disconnected from the measurement object
and a new measurement is started, the new measured value is
retained.

[HOLD] ashes: Waiting for stabilization of the measured value
[HOLD] appears: The measured value is retained

Conceptual diagram of auto-hold (AC voltage)

Indicated value

Measured
value

100 V 99 V

Auto-hold
Example: 100 V

Stabilized
range

Auto-hold is
not applied
(threshold is
not exceeded)

Auto-hold
Example: 99 V

Threshold allowing
auto-hold

Connect to the
measurement
object

36

Disconnect

Connect

Disconnect

Connect

Dead zone

Disconnect

Making Measurements in Voc Mode

Negative Voltage Notication Function

You can check whether P(+) and N(−) are connected in reverse

while measuring the open-circuit voltage of solar battery string.

When the voltage is −1 V or lower, red and white of the backlight
ash alternately.

1

Ground Fault Detection

Connecting the black test lead to the ground and red test lead to

N(−) or P(+) of the measurement object and measuring the voltage

allows a simple ground fault detection.

37

2

3

4

5

6

7

Appx. Index

Making Measurements in BPD TEST Mode

3.7 Making Measurements in BPD TEST Mode

To determine open fault and deterioration of bypass diodes
connected to a solar panel, measure the bypass diode and bypass
route resistance.

WARNING

Observe the following to prevent an electric shock,
short-circuit, or damage to the instrument.

• Do not measure under a live circuit condition.
Doing so could damage the instrument or cause an
accident that might result in injury or death. Always
turn off power to the measurement object before
starting.

• When measuring a bypass diode, dangerous
voltage is applied to the measurement terminals.
To prevent an electric shock, do not touch the test
leads.

• Press the MEASURE key fully down until a live circuit indicator lights up.

If the button is not pressed down fully, a proper measurement cannot be
made.

• After use, set the rotary switch in OFF.

38

Making Measurements in BPD TEST Mode

Lock Function

This function is used to avoid applying a measuring signal to
equipment. This function will prevent the test from starting even
if the rotary switch is set in BPD TEST and the MEASURE key is
pressed.

1

Canceling the lock function

Set the rotary switch in BPD

1

1

The screen is locked 1 minute after the last measurement or
operation again.

Flashes

Off

2

TEST.

RELEASE key ashes.

Press .

2

Pressing this key unlocks the
instrument and switches the
display to the measurement
screen.

2

3

4

5

6

7

Appx. Index

39

Making Measurements in BPD TEST Mode

Measuring Bypass Diode

CAUTION

To avoid electrical accidents, disconnect the solar
battery module from the commercial power circuit
before measuring.
Clusters with breakdown voltage 100 V or lower
cannot be judged correctly.

1

Release

(+)

(-)

P

N

2

Release the MEASURE key.

1

Set the rotary switch in BPD TEST.

2

Press to cancel the lock function.(p. 39)

Power conditioner,
Main switch

40

(+)

(-)

P

N

N(−)

3

4

Connect the black test lead to N(−) of

3

OFF

P(+)

String

the measurement object.

Connect the red test lead to P(+) of the

4

measurement object.

If the measurement object has an AC voltage

or its polarity is reversed, red and white ash

alternately on the backlight.

Release

7

Making Measurements in BPD TEST Mode

Press the MEASURE key.

5

Starts a measurement.
To make a continuous measurement,

(+)

(-)

P

N

6

raise the MEASURE key.

Check the judgment and

6

displayed values.

1

Press

5

Release the MEASURE key with the test leads connected to

7

the measurement object.

Ends the measurement.

• During measurement, do not switch over to other modes.

• The screen is locked 1 minute after the last measurement. To continue
the measurement, release the lock function. (p. 39)

• If negative voltage notication function is engaged, no measurement
starts. Verify the test lead connections once again.

• If the solar panel is not generating power due to the shielding of the light,

continuous measurement and negative voltage notication functions will

not be activated.

• The R

Measure all strings.

8

value will ash if the insolation varies during measurement

BPR

(for example, due to the movement of clouds). In this case, it will not

be possible to accurately measure the bypass route resistance. Repeat

measurement under conditions of consistent insolation

Press the MEASURE key once per string for measurements. If the result
is FAIL, verify the test lead connections once again.

Repeat the above procedure from 3 to 7.

2

3

4

5

6

7

Appx. Index

41

Making Measurements in BPD TEST Mode

After measurements are completed

Reconnect the lightning arrester connection if

1

disconnected.

Turn on all the disconnector devices of the strings.

2

Turn on the main switch of the connection box.

3

42

Bluetooth® Communication Function

3.8 Bluetooth® Communication Function

The instrument supports Bluetooth® low energy.
When the Bluetooth® function is enabled, you can review
measurement data and create measurement reports on mobile
devices (iPhone, iPad, iPad mini, iPod Touch, and Android™
devices).
For more information about this functionality, see the help function
in the application software GENNECT Cross.

Install the GENNECT Cross on

1

your mobile device. (p. 44)

Enable the Bluetooth® function

2

on the instrument.

Launch GENNECT Cross and

3

pair it with the instrument.
(p. 45)

Select the general

4

measurement function of
GENNECT Cross and make
measurements.

1

2

3

4

5

6

7

Appx. Index

43

Bluetooth® Communication Function

Installing the Smartphone Application Software GENNECT Cross

Search for “GENNECT Cross” on the App Store from your iPhone,
iPad or other Apple devices, or on Google Play™ from your Android
device. Then download and install the GENNECT Cross. You will
need an Apple ID to download the app from the App Store, or a
Google account to download the app from Google Play. For more
information about how to register an account, contact the store at
which you purchased your device.

• Because the instrument emits radio waves, use in a country or

region where it has not been approved may be subject to nes

or other penalties as a violation of applicable laws or regulations.
For more information, see the attached “Precautions Concerning

Use of Equipment that Emits Radio Waves” or go to our website.

• The availability of the instrument is limited to certain countries.
For more information, contact your authorized Hioki distributor or
reseller.

• Bluetooth® communications range varies greatly with distance
from obstructions (walls, metal obstruction, etc.) as well as

distance from the oor or ground. To ensure stable measurement,

verify adequate signal strength.

• Although this application software is provided free of charge,
downloading or use of the application software may incur Internet
connection charges. Such charges are the sole responsibility of
the user.

• This application software is not guaranteed to operate on all
mobile devices.

44

Bluetooth® Communication Function

Pairing the Application Software

1

1

Home > Other

• When the application software is
launched for the rst time (before

being paired with any instrument),
the connection setup screen will be
displayed.

• While the mobile device is displaying
the connection setup screen, simply
move it close to the instrument to
automatically pair it with the instrument
(the application software can be paired
with up to 8 instruments).

• Allow about 5 to 30 seconds for the
instrument to pair with the application
software after being turned on.
If the instrument fails to pair within 1
minute, relaunch GENNECT Cross and
cycle the instrument’s power.

• Pairing will be skipped when the
instrument is started next time after the
instrument has registered.

2

Instrument

Settings

3

The instrument is

automatically registered.

4

Returns to the

home screen.

2

3

4

5

6

7

Appx. Index

45

Bluetooth® Communication Function

Making Measurements with the Bluetooth® Function

On the home screen, select the standard measurement function
from the options, standard measurement, logging or waveform
display, to start a measurement. For more information about each
function, see the help function in the GENNECT Cross.
The values displayed by the instrument may be different from the
values displayed by the application software due to communication
delays or differences in the update timing.

Standard measurement

Measured values of multiple channels are saved.

46

Specications

4

4.1 General Specications

Operating
environment

Operating
temperature and
humidity

Storage
temperature and
humidity

Dustproofness and
waterproofness

Drop proof On concrete: 1 m

Standards Safety: EN61010

Power supply LR6 Alkaline battery × 6

Indoors, outdoors, Pollution Degree 2, altitude up to
2000 m (6562 ft.)

Temperature: −10°C (14°F) to 65°C (149°F)

Humidity:

less than 40°C (104°F),

80% RH or less (no condensation)

40°C (104°F) or higher but less than 45°C (113°F),

60% RH or less (no condensation)

45°C (113°F) or higher but less than 50°C (122°F),

50% RH or less (no condensation)

50°C (122°F) or higher but less than 55°C (131°F),

40% RH or less (no condensation)

55°C (131°F) or higher but less than 60°C (140°F),

30% RH or less (no condensation)

60°C (140°F) to 65°C (149°F),

25% RH or less (no condensation)

−20°C (−4°F) to 65°C (149°F),

80% RH or less (no condensation)

IP40 (EN 60529)

EMC: EN61326

Rated supply voltage: 1.5 V DC × 6
Power supply voltage range: 6.75 V to 10.35 V DC
Maximum rated power: 18 VA

1

2

3

4

5

6

7

Appx. Index

47

General Specications

Continuous
operating time

(Voc)

Possible number
of measurements

(BPD TEST)

Interface Bluetooth

When LR6 alkaline battery × 6 are used (at 23°C, as

a referential)

Approx. 45 hours (Comparator, LCD backlight,

®

Bluetooth

Approx. 18 hours (Comparator, LCD backlight,

Bluetooth

: Off)

®

: On)

LR6 Alkaline battery × 6 (at 23°C, as a referential)
Approx. 3000 times (Comparator, LCD backlight,

®

Bluetooth

: Off)

®

Dimensions Approx. 152W × 92H × 69D mm (5.98″W × 3.62″H ×

2.72″D)

Mass Approx. 650 g (22.9 oz.)

(including batteries, excluding test leads)

Product warranty

3 years

period

Fuse 3 A/1000 V fuse to protect from IGBT short-circuit

fault

(Cut-off capacity 30 kA, fast acting, φ10 × 38 mm:
SIBA GmbH)
Note: Replacement by user not allowed

Accessories Refer to “Verifying Package Contents” (p. 1)

Options Refer to “Options” (p. 2)

48

Input/Output/Measurement Specications

4.2 Input/Output/Measurement

Specications

Standard Specications

Measurement function Abbreviation Measurement function

Voc Open-circuit voltage

BPD TEST Bypass diode

SELF CHECK Self-check

Function conguration SELF CHECK/OFF/Voc/BPD TEST

Input terminal P(+) terminal: Connected to positive terminal of

N(−) terminal: Connected to negative terminal of

Maximum input voltage 1000 V DC

Maximum rated voltage

to earth

600 V DC (No measurement category)

measurement

measurement

PV string

PV string

1

2

3

4

5

(1) Voc mode

Measurement item Open-circuit voltage

Displayed item Open-circuit voltage

(Reference value and comparison value when

comparison display is enabled)

Measurement range 0 V to 1000 V DC (Displayed up to 1200 V DC)

Response time Within 1 sec.

6

7

Appx. Index

49

Input/Output/Measurement Specications

Comparison display Displays the difference from the measurement

Auto-hold Setting method:

(2) BPD TEST mode

Measurement

item

Displayed item Screen 1: Bypass route resistor, open-circuit voltage,

Measurement
object

Measurement

method

voltage with the auto-hold enabled for the rst

time or immediately after reset.

Valid only in the auto-hold state.
Displayed range: −100 V to 100 V
Maximum count: 100 counts

Overrange display: [>100 V] or [<−100 V] is
displayed.

Enable by placing the instrument’s MEASURE
key in the raised position or press and hold the

MEASURE key on a test-lead with remote switch.

Functionality:
When both the below conditions are met,

measured value is automatically held.

• Measurement voltage: 20 V or higher

• Fluctuation range of measurement voltage for

1

second: 20 V or less
Auto-hold update: A signal meeting the above
Auto-hold conditions is input after a measurement
voltage less than 20 V is input.

Bypass diode comparator judgment/Bypass route
resistor/Open-circuit voltage/Short-circuit current/

Applied current

Screen 2: The number of bypass diode measurements

Open-circuit voltage: 1000 V DC or less
Rated current: 2 A to 12 A DC
Crystal system string (Strings with a breakdown voltage
of 100 V DC or less cannot be measured.)

Short-circuit and pulse voltage application

short-circuit current, and applied current

50

Input/Output/Measurement Specications

Duration of

shorting between

terminals

Output pulse Voltage: 100 V DC or less

Judgment
method

Measurement

time

Current

measurement
method

Measuring range
for bypass route

resistance

(3) COUNT mode

Measurement

item

Number of

measurements

10 ms or less

Pulse width: 5 ms or less

Limiting current: Measured short-circuit current + 1 A or

Detected peak current ≥ Measured short-circuit current
+ additional current × 0.8: PASS
Detected peak current < Measured short-circuit current
+ additional current × 0.8: FAIL

condition can be added to the conditions above

R

BPR

with comparator setting.

2 seconds or less (3 seconds or less when
measurement voltage is 10 V or less)

Peak value detection

to 15

0

Ω

The R

BPR

current) varies during measurement.

Displays the number of bypass diode measurements

Counts the number of measurements from power on to

power off.
Resets the count to 0 when the power is turned off or
auto power save.

Maximum count: 199
More than 200 counts: [>199 V] ashes

less

Maximum: 13 A

Ω

value will ash if insolation (short-circuit

1

2

3

4

5

6

7

Appx. Index

51

Input/Output/Measurement Specications

(4) SELF CHECK mode

Measurement

item

Capacitor
discharge switch:

Short-circuit

IGBT:

Short-circuit

IGBT and capacitor discharge switch tests

Tests that capacitor discharge switch is not short-

circuited.

Fail: [Err5] is displayed.

Tests that IGBT is not short-circuited.
Fail: [Err4] or [oPn] is displayed.

Accuracy specications

Conditions of

guaranteed
accuracy

(1) Open-circuit voltage measurement

Range (displayed
range)

Accuracy range 0 V to ±1000 V

Accuracy ±0.2% rdg.±3 dgt.

Input impedance 1 M

Maximum count 1200 counts

Overrange display [>1200 V] or [<−1200 V] is displayed.

Guaranteed accuracy
period

Guaranteed accuracy
period from adjustment

made by Hioki

Temperature and humidity
for guaranteed accuracy

Power voltage range with
accuracy guarantee

Temperature
characteristic

1000 V (0 V to ±1200 V)

or higher

Ω

1 year

1 year

23°C±5°C (73°F±9°F),

80% RH or less

6.4 V to 10.35 V DC (One or
more battery levels appear)

Measurement accuracy ×

0.1/°C is added (other than
23°C±5°C).

52

Input/Output/Measurement Specications

(2) Short-circuit current measurement

Range (displayed
range)

Accuracy range 0.0 A to 15.0 A

Accuracy ±3% rdg.±3 dgt.

Input impedance 0.5

Maximum count 150 counts (The short-circuit current display will

Overrange display [>15.0 A] or [<0.0 A] is displayed.

(3) Bypass route resistance measurement

Range (displayed
range)

Accuracy range 0.0

Accuracy ±5% rdg. ±5 dgt.

Maximum count 150 counts

Overrange display [>15.0

Conditions of

guaranteed accuracy

15.0 A (0.0 A to 15.0 A)

or lower

Ω

ash if the value is greater than 13.0 A but less than
or equal to 15.0 A.)

15 Ω (0.0 Ω to 15.0 Ω)

to 15.0

Ω

During pure resistance measurement after the self­check has been performed
Accuracy is not guaranteed while the bypass route
resistance display is ashing.

Ω

] is displayed.

Ω

1

2

3

4

5

6

53

7

Appx. Index

Function Specications

4.3 Function Specications

Key input Refer to “MEASURE key” (p. 15), “Operation

Auto power save
(APS)

Indication Semi-transmissive FSTN LCD, positive

Battery indicator Battery voltage Battery level

16), and “Model L9788-10 Test Lead with

keys” (p.
Remote Switch (Red)” (p. 19)

Automatically turns

minutes after the last measurement (measurement

voltage is 5 V or less for Voc mode) with the power on.

Recovering from auto power save:

Set the rotary switch in OFF to turn off the power and

then turn on the power once again.

Refer to “Display” (p.

7.95 V±0.2 V or higher 3

7.35 V±0.2 V to 7.95 V±0.2 V 2

6.75 V±0.2 V to 7.35 V±0.2

6.75 V±0.2 V or less 0 (Battery

• Hysteresis
Low battery level remains even if battery voltage
increases but the power is not turned on once

again.

• Measurements cannot be carried out when battery

level is 0.
([bAt Lo] is displayed and automatically turns off
the power

off the power 15 minutes±1

17)

V 1

shape ashes)

.)

54

Function Specications

Live circuit indicator • Voc mode, SELF CHECK

Backlight White

Automatic polarity
judgment function

+20 V DC or higher or −1 V DC or less: Flashes
Other than the above: Off

• BPD TEST mode

MEASURE key is pressed: Lights up
MEASURE

Automatic light-off function available (The backlight
will turn off 3 minutes ±30 seconds after the last
measurement (or in Voc mode, after the measured
voltage falls to 5 V or less) or after the last operation.)

When measurement voltage is −1 V or less:

• Buzzer sounds, red backlight ashes, and white
backlight lights up.

• Auto-hold is disabled.

• Bypass diode measurement does not start.

When measurement voltage is 70 V

• Bypass diode measurement does not start.

• Buzzer sounds and red backlight lights up.

When measurement voltage is over −1 V to 10 V, and

when output pulse with limiting current of 0.1 A or less
is generated and measurement voltage is 90 V or

higher:

• Bypass diode measurement does not start.

• Buzzer sounds and red backlight lights up.

key is released:

+20 V DC or higher or −1 V DC or less: Flashes
Other than the above: Off

AC or higher:

0-P

1

2

3

4

5

6

7

Appx. Index

55

Function Specications

Comparator • Voc

Threshold value can be set in 1 V increments from
0 V to 20 V for the absolute value of Voc diff.

• BPD TEST mode
Threshold value can be set in 0.5

from 0

Judgment is available only when the auto-hold is
enabled.

Voc diff ≥ Threshold value: FAIL
Voc diff < Threshold value: PASS

increments

to 15 Ω for R

Ω

≥ Threshold value: FAIL

R

BPR

< Threshold value, and

R

BPR

Detected peak currentd < Measured short-circuit

BPR

Ω

.

current + additional current × 0.8: FAIL
Detected peak current ≥ Measured short-circuit
current + additional current × 0.8: PASS

56

4.4 Interface Specications

Interface Specications

Interface

Antenna power Maximum +0 dBm (1 mW)

Communication distance 5 m (line of sight)

Communication prole GATT (Generic Attribute Prole)

Supported Android
devices

Supported iOS devices iOS10 or later

®

Bluetooth

Android4.3 or later

(Bluetooth

(Bluetooth

4.0LE ( )

®

low energy enabled devices)

®

low energy enabled devices)

4.5 Factory Settings

Settings state Setting backup

Auto power save Enabled N/A

Comparator Enabled

®

Bluetooth

setting Enabled Available (On/Off)

Voc diff: 10 V

: 2.5

R

BPR

Ω

Available
(On/Off, preset)

1

2

3

4

5

6

7

Appx. Index

57

Factory Settings

58

Maintenance and Service

5

WARNING

Touching any of the high-voltage points inside
the instrument is very dangerous. Customers are
not allowed to modify, disassemble, or repair the

instrument. Doing so may cause a re, an electric

shock, or a injury.

Calibrations

The calibration period varies depending on the status of the
instrument or installation environment. We recommend that the
calibration period be determined in accordance with the status of
the instrument or installation environment. Please contact your Hioki
distributor to have your instrument periodically calibrated.

Precautions when transporting the instrument

When transporting the instrument for repair or any other purpose,
be sure to observe the following precautions:

• To avoid damage to the instrument, remove the batteries from
the instrument. Moreover, be sure to pack in a double carton.
Damage that occurs during transportation is not covered by the
warranty.

• When sending the instrument for repair, be sure to include details
of the problem.

Disposal

Handle and dispose of the instrument in accordance with local
regulations.

Cleaning

• To clean the instrument, wipe it gently with a soft cloth moistened
with water or mild detergent.

• Wipe the LCD gently with a soft, dry cloth.

• Wipe the dust from metal parts of alligator clips with a soft cloth to
avoid any impact on the measurements.

59

1

2

3

4

5

6

7

Appx. Index

Troubleshooting

5.1 Troubleshooting

Before Returning for Repair

If damage is suspected, check the “Troubleshooting” section below
before contacting your authorized Hioki distributor or reseller.

Symptom Check Items Remedy and Reference

Measurements
cannot be
performed in BPD
TEST mode.
Pressing the

MEASURE key in

BPD TEST
enables the lock
function that has
been released.

Is the function to prevent
the application of voltage
by mistake locked?

Does the battery have

sufcient charge?

mode

Are you using alkaline
batteries?
Has 1 minute lapsed
after the last operation?

Release the lock function.
(p.

39)

Replace the batteries with new
alkaline batteries. (p. 22)

Release the lock function
again. (p. 39)

The MEASURE
key of test lead
with remote switch
is not working.
Measured value
is not displayed
correctly.

The batteries run
out immediately.

60

Is the plug of the test
lead with remote switch
fully inserted?

Is there a broken
connection in a test
lead?
Are the test leads
securely connected?

Are you using alkaline
batteries?

Fully insert the plug to the limit
without any gaps. (p. 24)

Check the continuity of the test
lead with a tester.

Check the connection
between the test leads and
the instrument, and check the
connection of the tips of the
test leads.

Replace the batteries with
alkaline batteries. (p. 22)

Troubleshooting

Symptom Check Items Remedy and Reference

The power is not
turning on.

Does the battery have

sufcient charge?

Have the batteries been
installed properly?

Replace the batteries with new
alkaline batteries. (p. 22)

Install the batteries in the
proper orientation. (p. 22)

1

Error Displays and Remedies

When an error is displayed on the LCD screen, repair is necessary.
Contact your authorized Hioki distributor or reseller.

Error

indication

Description Remedy and Reference

Zero-adjustment error
(resistance value of 3

or greater during the

Ω

self-check)

Failure of EEPROM
that holds measured
data
(If you encounter an
EEPROM error, reset
the instrument to its
factory defaults.)

Corrupted adjustment
data

IGBT short-circuit fault Repair is required.

Discharge switch short­circuit fault

Check whether the test lead is
unplugged.

Turn off power and turn on the
power once again.

Repair is required.

Repair is required.

2

3

4

5

6

7

Appx. Index

61

Troubleshooting

Discharge capacitor life
(Displayed once
800,000 cycles are
reached.)

Bluetooth® is broken Repair is required.

Repair is required.

AC voltage input

Low battery voltage

1 VΩ or greater input
during the self-check

Bypass diode is open
or input is open

Verify that you have
connected the instrument
properly.

Replace the batteries.
(p.

22)

Check whether the test
lead is connected.

62

Appx.

Appx. 1 Measurement Principles

Measurement Principles for Bypass Diodes with an Open Fault

Measure a short-circuit current of a solar panel

1

Apply current to a solar panel

2

Applied current (IB) = Short-circuit current (IA) + 1 A current

• If short-circuit current (I
working correctly (OK).

• If short-circuit current (I
an open fault.

Bypass diode

P

N

(+)

(-)

P

N

P

N

Applied current

Pass: I

< I

A

B

) < applied current (IB), the bypass diode is

A

) = applied current (IB), the bypass diode has

A

1

Short-circuit current Applied current

P

N

(+)

(-)

P

N

I

A

2

P

N

P

N

Normal

False: I

A

Open fault

= I

B

(+)

(-)

P

N

V

I

B

B

1

2

3

4

5

6

7

Appx. Index

Appx.1

Measurement Principles

Measurement Principles for Bypass Diodes with a Short-circuit Fault

Measure an open-circuit voltage of a reference solar panel

1

(= reference voltage)

Measure an open-circuit voltage of another solar panel

2

(= measurement object voltage)

• If reference voltage (VA) = measurement object voltage (VB),
the bypass diode is working correctly (OK).

• If reference voltage (V
the bypass diode has a short-circuit fault.

) > measurement object voltage (VB),

A

Bypass diode

1

P

Reference panel Another panel

P

N

(+)

(-)

P

N

A

N

(+)

(-)

P

N

V

A

P

2

P

B

N

(+)

(-)

P

N

V

V

B

B

P

B B

N

(+)

(-)

P

N

Pass: VA = V

B

Normal Short-circuit fault

N

False: V

(+)

(-)

P

N

> V

A

B

Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176

TestEquipmentDepot.com

Appx.2